Convert images to web-friendly formats

Make your images visible on the web


In a world where the iPhone 5s can produce images at an impressive resolution of 3264 × 2448, and with hardware only improving, the snaps that we are taking are getting larger in size – both in dimensions and megabytes.While these numbers are great if you wish to share your images on a large screen – the high resolution means they’ll be able to be shown on large displays without pixelation – if you’re looking to put them on the web it’ll take longer and may take up a lot of screen space.
Fortunately, there are several ways to convert images and reduce their size and dimensions using OS X’s built-in apps. Here we look at how the Preview app and Automator scripts can work together to get you suitable shots in no time at all.


1 Choose your image

We’ve edited our image in Photoshop and saved it as a .psd. The result is a relatively massive file size of over 100MB – far too large if we were looking to share it on social networks.


2 Open in Preview

Double-click your image. In the event that it opens in an app other than Preview (a .psd may open in ColorSync Utility), Ctrl-click the image and choose Open With. Select Preview.


3 Convert the image

With the image open, click File>Export. Click on the Format drop-down box to select your chosen format. We’ve chosen JPEG, and already there’s a marked drop in size – nearly 100MB.


4 Reduce size

We can make the file size even smaller without a noticeable drop in quality by editing the dimensions. Go to Tools>Adjust Size and click percent in the Width/Height drop-down.


5 Batch editing

You may want to set up an Automator script. Open Automator and choose Application. Pick Photos from the left and drag Change Type of Images and Scale Images into the main window.


6 Tidy up with folders

To keep your desktop tidy, you can add an order to your script that copies the resized images to a different folder. Go to Files & Folders on the left and drag Copy Finder Items into your script.